Question: Simplify the following expression: $a = \dfrac{-55z}{11z + 88}$ You can assume $z \neq 0$.
Find the greatest common factor of the numerator and denominator. The numerator can be factored: $-55z = - (5\cdot11 \cdot z)$ The denominator can be factored: $11z + 88 = (11 \cdot z) + (2\cdot2\cdot2\cdot11)$ The greatest common factor of all the terms is $11$ Factoring out $11$ gives us: $a = \dfrac{(11)(-5z)}{(11)(z + 8)}$ Dividing both the numerator and denominator by $11$ gives: $a = \dfrac{-5z}{z + 8}$